640747575 has 36 divisors (see below), whose sum is σ = 1235936520. Its totient is φ = 315443520.

The previous prime is 640747567. The next prime is 640747577. The reversal of 640747575 is 575747046.

640747575 is a `hidden beast` number, since 6 + 4 + 0 + 74 + 7 + 575 = 666.

It is not a de Polignac number, because 640747575 - 2³ = 640747567 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 640747575.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640747577) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 106605 + ... + 112454.

It is an arithmetic number, because the mean of its divisors is an integer number (34331570).

Almost surely, 2^640747575 is an apocalyptic number.

640747575 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

640747575 is a deficient number, since it is larger than the sum of its proper divisors (595188945).

640747575 is a wasteful number, since it uses less digits than its factorization.

640747575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219088 (or 219080 counting only the distinct ones).

The product of its (nonzero) digits is 823200, while the sum is 45.

The square root of 640747575 is about 25312.9922174365. The cubic root of 640747575 is about 862.1092874321.

The spelling of 640747575 in words is "six hundred forty million, seven hundred forty-seven thousand, five hundred seventy-five".